Air-to-Air missile (AAM)

An air-to-air missile (AAM) is a weapon mounted on fighter aircraft for use in air combat. Well-known AAMs include the Sparrow and Sidewinder of the
United States. As recent progress in missile guidance technology has improved the hit probability, missile performance determines the result of air battles. AAM Trends AAMs are categorized according to their range, roughly
into short-range missiles (SRMs), medium-range missiles (MRMs), and long- range missiles (LRMs).

SRM Like the machine gun, the SRM is a basic weapon in air combat when friendly and enemy aircraft fight at very close range. SRMs have been developed and deployed by many countries. Guidance is by an infrared system that tracks the infrared rays radiated from the exhaust heat of aircraft
engines. As this system can trace the target without the missile emitting radio waves, it is advantageous in its freedom from electronic counter measures (ECM) and is relatively undetectable by the enemy. Its disadvantage is that it tends to be affected by the weather.

A typical SRM is the Sidewinder (AM-9) series of the United States. However, its range is limited to the rear of the enemy because it must track the exhaust heat from aircraft engines. The next generation SRM is expected to
evolve toward a missile which can attack in any direction thanks to progress in the infrared sensor and electronic circuit technology. It will also feature improvements in its turning ability, background identification capability,
and off-boresight capability (ability to be launched to attack a target which is not located in front of the launching aircraft).

The MRM is mainly used to intercept targets located outside SRM range. For this purpose, the MRM uses a radar homing system with a greater detection range and better all-weather properties than the infrared guidance system.
But this system requires ECM to be taken into consideration because it uses radio waves for acquiring and tracking the target. The MRM is subject to
severe limitations in terms of size and weight because it should be mounted on a fighter, and each component is required to be compact. Particularly, in an active radar homing system, the transmitter radiating radar waves should
be incorporated in a guidance control block.

As seen in the Gulf war, recent improvements in guidance control technology and long-range friend/foe identification capability of search radar have led to an increase in the usefulness of MRMs. Previous MRMs used to use semi-active radar homing systems of the type seen in the Sparrow (AIM-7F/M) of the United States. With this system, the missile tracks the target by receiving the reflections of radar waves emitted from the launching aircraft by the target. The launching aircraft cannot fly freely until the missile hits the target because it must continue emitting radar waves at the target. To overcome this drawback and allow the launching aircraft to retreat after launching the missile, the need for an active radar homing system using radar waves transmitted from the missile itself has been recognized and studied by many countries. The countries developing or operating missiles incorporating active radar homing systems include the United States and Russia. The
model already used in the United States is the AMRAAM (AIM- 120).

Such LRMs as the U.S. Phoenix (AIM-54C) and Russian AMOS (AA-9) have ranges close to 200 km. To destroy organized combat capability using early warning and control aircraft and ECM aircraft, the need for missiles with higher
speed and longer range are increasing. This is recognized internationally and countries throughout the world are conducting research in this direction.